The short answer is probably “yes,” though it depends on what you are trying to achieve. If you have to stick an RFID transponder in wet soil, then you will need to use a low-frequency (LF) or high-frequency (HF) tag, and the read range will likely be around 6 inches or so. If you want to track plants from a longer range, however, then you can place an ultrahigh-frequency (UHF) tag on the outside of a plant bucket, or hang it from the plant itself.
Container Centralen is tagging the racks that customers use to ship plants (see Container Centralen to Monitor Millions of Crates), as well as the metal carts containing the racks (see Container Centralen Adds Active Tags to U.S. Carts).
So there are a variety of options, depending on what data you need to collect, where you need to collect it and options available for tagging the horticultural products, the containers in which they are shipped and so forth.
Here are a few other articles that might be of interest:
—Mark Roberti, Founder and Editor, RFID Journal
Will RFID Prices Come Down in the Near Future? »